Wigner RCP 2018

Wigner RCP 2018

Annual Report

Wigner Research Centre for Physics

Hungarian Academy of Sciences

Budapest, Hungary

2019

Wigner Research Centre for Physics Hungarian Academy of Sciences Budapest, Hungary

2019

Published by the

Wigner Research Centre for Physics, Hungarian Academy of Sciences Konkoly Thege Miklós út 29-33 H-1121 Budapest

Hungary

Mail: POB 49, H-1525 Budapest, Hungary Phone: +36 (1) 392-2512

Fax: +36 (1) 392-2598

E-mail: titkarsag@wigner.mta.hu http://wigner.mta.hu

© Wigner Research Centre for Physics ISSN: 2064-7336

Source of the lists of publications: MTMT, http://www.mtmt.hu This yearbook is accessible at the Wigner RCP Homepage, http://wigner.mta.hu/en/yearbook

Wigner RCP 2018 – Annual Report

Edited by T.S. Biró, V. Kozma-Blázsik, B. Selmeci Proofreader: I. Bakonyi

Closed on 15. April, 2019

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List of contents

Foreword from the Director of the Institute for Solid State Physics and Optics ... 6

Awards and prizes ... 8

Key figures and organizational chart ... 10

Wigner and ESA Technology Transfer Program ... 12

International scientific cooperation ... 15

Outstanding research groups ... 17

R-A. Field theory ... 18

R-B. Heavy-ion physics ... 21

R-E. Holographic quantum field theory ... 31

R-G. “Lendület” innovative gaseous detector development ... 35

R-I. Femtosecond spectroscopy and X-ray spectroscopy ... 39

R-J. Functional nanostructures ... 45

R-Q. Space physics ... 48

S-A. Strongly correlated systems ... 53

S-B. Complex systems ... 60

S-D. Semiconductor nanostructures ... 66

S-H. Partially ordered systems ... 71

S-J. Gas discharge physics ... 76

S-P. Ultrafast, high-intensity light–matter interactions ... 82

S-S. Quantum optics ... 85

S-T. Quantum information and foundations of quantum mechanics ... 89

Institute for Particle and Nuclear Physics ... 94

R-C. Gravitational physics ... 95

R-D. Femtoscopy ... 100

R-F. Hadron physics ... 105

R-H. Standard model and new physics ... 111

R-K. Ion beam physics ... 115

R-L. Cold plasma and atomic physics in strong fields ... 118

R-M. ITER and fusion diagnostic development ... 122

R-N. Laser plasma ... 125

R-O. Beam emission spectroscopy ... 128

R-P. Pellet and video diagnostics ... 133

R-R. Space technology ... 140

R-T. Theoretical neuroscience and complex systems ... 142

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R-U. Neurorehabilitation and motor control ... 145

R-V. Data and Compute Intensive Sciences ... 147

Institute for Solid State Physics and Optics ... 149

S-C. Long-range order in condensed systems ... 150

S-E. Non-equilibrium alloys ... 156

S-F. Laboratory for advanced structural studies ... 159

S-G. Radiofrequency spectroscopy ... 163

S-I. Electrodeposited nanostructures ... 165

S-K. Liquid structure ... 169

S-L. Nanostructure research by neutron scattering ... 174

S-M. Neutron optics ... 181

S-N. Laser applications and optical measurement techniques ... 184

S-O. Femtosecond lasers for non-linear microscopy ... 187

S-Q. Crystal physics ... 193

S-R. Nanostructures and applied spectroscopy ... 196

The Research Library ... 200

Supplementary data ... 202

Education ... 203

Dissertations ... 214

Memberships ... 215

Conferences ... 225

Wigner Colloquia ... 231

Seminars ... 232

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FOREWORD

from the Director of the Institute for Solid State Physics and Optics

It is my privilege to present, for the final time before my retirement, the 26^th edition of the Annual Report of the Institute for Solid State Physics and Optics of the Wigner Research Centre for Physics. During my career at the Institute spanning 41 years we underwent two restructurings. The first in 1992, when the well-known Central Research Institute for Physics of the Hungarian Academy of Sciences (KFKI) was split into four independent institutions, followed by the second in 2011, when our institute merged with the Institute for Particle and Nuclear Physics, to form the Wigner Research Centre for Physics. Over the last four decades much has changed: the Soviet Bloc collapsed, our social and economic system changed, and travel without restrictions became possible. It was an exciting era when the world opened and expanded around us. During this transition period it was a great challenge, with my colleagues, to overcome all the new obstacles. This made our lives vibrant, colourful, and adventurous.

I am pleased to announce that 2018 was yet another successful year for the Institute of Solid State Physics and Optics. In today’s world, competitiveness of a nation and success of a society is increasingly determined by its human potential: its well-educated and creative members abounding with ideas and readiness to make a contribution (in Count István Széchenyi’s rather freely translated words). This is even more pronounced in scientific research and development where new insights and inventiveness play crucial roles.

The core mission of management is to maintain the necessary environment in which our research groups can prosper and achieve outstanding scientific results. Regardless of the new plans for yet another reorganization that has gained traction over the past mouths, our staff remains motivated, our scientists continue to work assiduously, and their considerable efforts have earned significant recognition from both our local scientific community and from a much wider national and international audience. One colleague received the Széchenyi Prize, a major award by the state recognizing outstanding contributions to academic life in Hungary.

The activities of all four Lendület (Momentum) Research Groups exceeded expectations. The leader of the Strongly Correlated Systems group won the Humboldt Research Award. A young scientist from the Semiconductor Nanostructures Lendület Group received the Young Investigator Finalist Award for his research, while PhD students and postdocs received Scholarships from the Ministry of Human Resources a Tempus Mundi Internship and membership of the Premium Postdoc Program of HAS. The Ultrafast, high intensity light- matter interactions Lendület Group is a Max Planck Partner Group. Last but not least, the Quantum Optics Lendület Group became the consortium leader of the more than 1 million Euro HunQuTech project. The institute currently has another four outstanding groups, the Wigner Research Groups, which we hope will grow to become future Lendület groups or project leaders. It has become a tradition at the institute to award prizes for outstanding publication activity as well as for applied research. This year an ambitious PhD student from

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the Semiconductor Nanostructures Lendület Group won this prize based on his high impact factor articles, notably published in Nano Letters and Nature Communications.

The present yearbook highlights our activities and presents the organization that we have developed throughout the years. We briefly summarize our 2018 scientific activities and the achievements of our 20 research groups. For this purpose, we list selected publications, grants and contracts, as well as applications and related academic and outreach activities.

Of the total of 204 papers authored by our researchers in 2018, approximately two-thirds have foreign co-authors, highlighting our colleagues’ strong ties with researchers in over 30 countries, primarily in the European Union, but also in many other international universities and research institutions. The institute interacts with 45 foreign universities and institutions, among which 18 are German, 8 American and 4 Japanese. Among the 18 research institutions with whom we collaborate 15 are in the EU and associated countries and one in each of Australia, Egypt and Japan.

Our scientists’ achievements are acknowledged through a number of international contracts and collaborations such as the H2020 RI projects including BrightnESS and IPERION-CH, the FET Open projects such as NEURAM and Petahertz Opt. Com, VISGEN as our first MSCA Rise project and collaborations like ASTERIQs. In the field of quantum technology there is the HunQuTech consortium led by our institute and two additional Quant ERA projects. The V4- Korean, the Japanese-Hungarian collaboration programs, and the two NKP and KKP National Excellence Programs are among the most significant.

Such accomplishments play a key role in keeping excellent researchers at our institute in spite of the strong brain drain, not only to more scientifically developed countries, but increasingly to local industry. Competitiveness and success can only be achieved by bolstering human potential. Our priority challenge is to provide a modern scientific infrastructure in an inspiring intellectual environment to attract and retain the most talented students and young researchers.

I hope this booklet will provide you with useful information regarding the development of the institute and its main achievements in the fields of quantum optics, solid state physics, laser physics, applied and nonlinear optics, complex fluids, neutron spectroscopy and a number of applications – e.g. in environmental science, biology, pharmacology, toxicology, medicine, etc.

This publication is directed not only at the scientific community, but to all interested readers in Hungary and abroad who would like to catch a glimpse of the activity of our institute as witness to milestones in the history of Hungarian science.

Aladár Czitrovszky

director of the Institute for Solid State Physics and Optics of the Wigner Research Centre for Physics

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AWARDS AND PRIZES

Awards of the State of Hungary and Government of Hungary L. Gránásy, Széchenyi award

Awards of the Hungarian Academy of Sciences

L. Szabados: Physics Prize of the Hungarian Academy of Sciences K. Szegő: Eötvös József Wreath Award of the HAS

T. Pusztai: Prize of the HAS

International professional awards

T. Csörgő (representing TOTEM-Hungary): TOTEM 2018 Achievement Award, by the Spokesperson and the Chair of the Collaboration Board, TOTEM Collaboration F. Nemes: TOTEM 2018 Publication Award, by the Spokesperson and the Chair of the Collaboration Board, TOTEM Collaboration

D. Kincses: Fulbright Student Award (US-Hungarian Fulbright Foundation for Educational Exchange) to SUNY Stony Brook (Prof. Roy A. Lacey, supervisor)

M. Varga-Kőfaragó: ALICE thesis award

L. Földy, NASA Group Achievement Award to Cassini Plasma Spectrometer Team

Sándor Szalai and the Space Technology Group: NASA Aeronoutics and Space Administration Group Achievement Award to Cassini Spectrometer team

P. Érdi, Florence J. Lucasse Fellowship for Excellence in Scholarship.

Ö. Legeza: Humboldt Research Award

V. Ivády: Among the five finalist Psi-k Volker Heine Young Investigator Award, 2018 A. Czitrovszky: honorary member of the Ukraine Academy of Sciences and Education National professional awards

R. Kovács: Györgyi Géza Prize of the Wigner RCP of the HAS 2018 M. Varga-Kőfaragó: Wigner RMI Directors praise

A. Opitz: ELFT Jánossy Lajos Award.

G. Thiering: Publication Award of the Wigner RCP SZFI G. Thiering: György Ferenczi Memorial Award

A. Derzsi: ELFT Schmid Rezső Award 2018

Bolyai János Scholarship of the HAS granted in 2018

G. Barcza Sz. Szalay L. Temleitner Sz. Pothoczki

B. Mikóczi P. Kovács D. Nagy A. Vukics

New National Excellence Program (ÚNKP) scholarships

B. File M.A. Pocsai Sz. Szalay D. Beke

A. Csóré L. Kocsor É. Tichy-Rács N. Kiss

9 Other scholarships

B. File: EFOP-3.6.3-VEKOP-16-2017-00002, Non-conventional computational and modelling approaches (PPKE-ITK)

Á. Gali: KKP Élvonal (Excellence Grant), NKFIH Grant No. 129886 V. Ivády: Premium Postdoctoral Programme of the HAS

A. Csóré: Tempus Mundi Internship

N. Kiss:International Investigative Dermatology International Trainee Retreat scholarship, Orlando, FL

Other awards

D. Kincses: SCIndicator of the Year prize (SCIndikátor science-communication quiz) D. Kincses: Audience Award (SCIndikátor science-communication quiz)

Oláh László, Balogh Szabolcs József, Hamar Gergõ, Varga Dezsõ, Gera Ádám László, Nyitrai Gábor, Pázmándi Zsolt: Award of Excellence, Fizikai Szemle

G. Thiering: Publication prize (1st) of the Department of Atomic Physics, BME

N. Kiss:Semmelweis University Excellent Management of Undergraduate Students award.

N. Kiss:Trialect for Non-Invasive Diagnostic, Surgical, and Cosmetic Dermatology Fellowship, Rome.

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KEY FIGURES AND ORGANIZATIONAL CHART

Permanent staff by profession

Total: 376

Scientists by degree/title

Total: 212

Scientists by age group

Total: 212

Income

Expenditure

*V.A.T not included.

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WIGNER AND ESA TECHNOLOGY TRANSFER PROGRAM

Zsuzsanna Tandi – Innovation Adviser and Head of the European Space Agency ‘National Technology Transfer Initiative in Hungary’

and ESA Business Incubation Centre Hungary

In 2013, Wigner Research Centre for Physics of the Hungarian Academy of Sciences (Wigner RCP HAS) established the position of Secretary of Innovation to promote the industrial exploitation of the results generated during the researches. The Wigner RCP HAS has developed its Intellectual Property Right Rules and the administrative background pursuant to the regulations of the Headquarters of the Hungarian Academy of Sciences and the current laws.

The management have attended numerous events and conferences, which provided opportunities to meet industrial partners, demonstrate the Institute’s capabilities, and the potentials of a cooperation with MTA Wigner RCP. The research teams of the Institute have successfully completed industrial orders.

In 2016, we established our Technology Transfer Office in association with the European Space Agency (ESA). Since December 6, 2016, the office has been operating the “National Technology Transfer Initiative in Hungary” (NTTI) programme with the approval of the Ministry of National Development and ESA. The programme made it possible for the Office to expand to 7 people (3 persons in full time and 4 in part time).

As a result of the successful implementation of the ESA NTTI programme, the second pillar of the ESA Technology Transfer Programme has also opened up for Hungary. ESA and the Ministry of National Development (later the Ministry of Foreign Affairs and Trade) repeatedly selected the Wigner RCP HAS as a partner to implement the second pillar in Hungary. Signing the contract on June 27, 2018, we were granted the right to open the Business Incubation Centre (BIC) of ESA as a joint programme of the Hungarian Academy of Sciences and ESA. The incubator programme was launched on July 2, 2018.

Opening ceremony of the ESA Business Incubation Centre Hungary: Martin Kern, EIT interim director; Levente Magyar, Deputy Minister of Foreign Affairs and Trade;

Johann-Dietrich Wörner, ESA Director General; Zsuzsanna Tandi, Head of ESA BIC Hungary; Ádám Török, F.M., Secretary- General of HAS, Péter József Lévai, Director General of Wigner RCP HAS

The Business Incubator and the NTTI operate with the same staff and at the same location. This merger of the two programmes, which was

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also an innovation within the ESA network, are working successfully in synergy, earning a strong reputation among the other 20 international ESA offices.

Since 2013, the Secretary of Innovation is also a member of the HEPTech project at CERN (High Energy Physics Technology Transfer Project). In May 2017, she was also invited to the ARIES (Accelerator Research and Innovation for European Science and Society). These steps deemed necessary for the professional handling of intellectual property generated by the research institute. Being a part of these institutions, we acquired refined protocols, well- functioning frameworks that is of great help during the implementation of the ESA Technology Transfer Program.

The Hungarian ESA ‘National Technology Transfer Initiative’ office is one of the 4 priority ESA offices. The Office has its own source of applications, and provides support for demonstration projects. The Hungarian Office supports continuously many technology transfer projects and financially supports 2 projects per year as grants.

The research teams will have the opportunity to communicate with industrial partners of the Incubator program. They can receive continuous feedbacks in relation to their research. In addition, maintaining live connection they can get investor resources. Thanks to the infrastructural support of the Hungarian Academy of Sciences, the Incubation Centre was given the opportunity to operate in a fully renovated and equipped, almost 450 m² modern environment at the KFKI campus, which is open to the researchers of the Hungarian Academy of Sciences.

Training room of ESA BIC Hugary Corridor of ESA BIC Hungary

Our objective is to contribute to the economic development of Hungary, strengthen businesses, create jobs, and help to launch new ventures. In addition, our network encourages Hungarian entrepreneurs to launch businesses abroad.

ESA Business Incubation Centre Hungary has become the member of ESA BICs network providing support all over Europe. ESA BIC Hungary (and the ESA NTTI Hungary also) helps to transfer technology from space to non- space applications and will support 25 Hungarian start-ups over a 5-year period to develop products for terrestrial use. It executes the overall implementation and management, such as

 supporting start-ups during the incubation phase by providing accommodation, business and technical support and coordination,

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 identifying Financial Partners to provide access to finance, loan schemes or seed equity funds;

 supporting the selected applicants during the execution of the activities in order to achieve meaningful results;

 organising events and training

Presswall of ESA BIC Hungary

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INTERNATIONAL SCIENTIFIC COOPERATION

Valéria Kozma-Blázsik, scientific secretary

Every year ushers in new scientific and societal advancements, challenged by new risks and threats, steadily raising the expectations placed by society. Scientific research is an area of constant change and progress that requires great flexibility from its participants to adapt quickly to a continuously evolving environment. The year 2018 started like a typical year; scientists continued with their research, published new articles, carried out experiments, developed and built new equipment to implement their project goals. Thanks to their great energy and motivation, 2018 turned out to be yet another success.

As in previous years, Wigner’s research teams continued to harness their strengths, publishing in high ranking scientific journals, actively participating in the Hungarian higher education system, and tirelessly writing grant proposals to expand their horizons and financial means.

Wigner’s research groups cover a wide range of specialities within physics as reflected through their publications. In 2018, altogether 870 scientific publications were published by members of the two institutes. Of these 651 articles from RMI, a great proportion in large collaborations mainly partnering with CERN, and 217 from SZFI in different topics of material sciences, photonics and quantum optics.

The largest portion of the articles are the result of collaborative projects. This year researchers participated in around 75 projects, among them 13 EU, 6 non-EU but internationally funded such as ESA, NIH etc., and 53 national projects of various kinds with grant amounts above 5 million HUF (about €15.000), in addition to about 30 smaller mobility projects. Researchers took part in 20 consortia with international and Hungarian partners, mainly from universities and other research institutes. Finally, there were a dozen long-term and a handful of new collaborations with industrial partners.

We mention the applications of cosmic muons for large-scale imaging among the successful research directions at the Institute of Particle- and Nuclear Physics in recent years. An important application of cosmic muons detectors was developed for the imaging interiors of volcanos. The Japanese NEC company licensed our muography observation system (MOS) for research purposes, and extended its licensing rights and committed funding for the coming year. During the term 2017 - 2021 the Institute of Solid State Physics and Optics is acting as coordinator of the HunQuTech Consortium in the framework of the National Excellence Program 2017 on Quantum Technology with a budget of 3,5 billion HUF. This year alone the research centre administered 3,1 billion HUF of project revenue (approx. 9,8 M €).

Researchers of the Wigner Research Centre are very active in Hungarian academic education and the Doctoral Schools. They continuously build strong ties with their many university students, mentoring them during their Masters theses, TDK projects, and PhD degrees.

However, during the last few years we had to address a new set of challenges including high turnover rates mainly among our young scientists. From year to year it is increasingly difficult to attract young talent. To counter this process on the long term, we increasingly focus on

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outreach activities towards the high school generation, and organize events such as Open Days, and Girls’ Day to awaken early interest in scientific careers. In 2018, we organised our first five-day Summer Camp for 10 students, during which they carried out a small project at the 5 participating laboratories. Motivated by the success of this initiative we plan to repeat it in the framework of a longer 10-day program, which would enable students to gain deeper insights to their topic of choice. It was also the first year that we offered internships to students studying at UK universities. We hope that providing them with a first-hand working experience at our institutes will offer them a long term alternative to leaving the country.

Our research centre must compete not only with the allure of research possibilities abroad, but also with the strong financial incentives offered by industry. If this now one-way mobility into industry would be flowing equally in both directions, it would be present young researchers with invaluable means for gaining experience. Our MSCA Visgen RISE project is setting the example for this new type of academia-industry bidirectional relationship.

In the first 6-7 months of the year business was as usual, but by mid-year we were faced with the possibility of yet another reorganisation, the second since 2012, when the Wigner Research Centre for Physics was founded. Since then we have made considerable steps to create a fresh organisational culture, building on the strength of the two merging research institutes of the former KFKI campus. We owe thanks to a few significant national VEKOP projects awarded in the last two years that provided the financial means to catalyse this process. Based on this revenue we could build and strengthen interdepartmental and interdisciplinary cooperation with ‘Lendület’- Momentum groups from both institutes RMI and SZFI working together on Ultrafast experiments for better functional molecules, nanocircuits, and atomic beams.

For the past 11 years, I have been working for Wigner and its predecessor institute. I am witness to the new developments of a continuously evolving ecosystem. We do our best to find novel ways to introduce new innovative ideas and transform to achieve our goal of becoming a true learning organisation.

Once again, we can conclude that the significant achievements of Wigner during the past year reflect the hard work of our people and our commitment to make a difference through:

Looking outwards to listen and respond to society, engage constructively with academic professionals, government, and industry;

Looking forwards to respond effectively to emerging challenges, benefiting from emerging knowledge and technologies; and

Looking after our people and the resources entrusted to us in order to search for and give scientific answers to pressing issues of our contemporary world.

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OUTSTANDING RESEARCH GROUPS

MTA’s “Momentum” Research Teams

The goal of the “Momentum” Program of the Hungarian Academy of Sciences (HAS) is to renew and replenish the research teams of the Academy and participating universities by attracting outstanding young researchers back to Hungary. The impact and success of this application model is highly acclaimed and recognised by the international scientific community. Initiated by the former HAS President József Pálinkás, the “Momentum” Program aims to motivate young researchers to stay in Hungary, provides a new supply of talented researchers, extends career possibilities, and increases the competitiveness of HAS' research institutes and participating universities.

Wigner Research Groups

The “Wigner Research Group” program is introduced to provide the best 3-3 research groups from both institutions of the Centre with extra support for a year. Its primary goal is to retain in science and in the Research Centre those excellent young researchers who are capable of leading independent research groups. It aims to energize research groups, and to recognize, support and raise the profile of the leader of the group. During the support period the research group should make documented efforts to perform successfully on domestic R&D tenders and international tenders of the EU and its member states.

* Abbreviations in the researcher lists of the scientific projects:

#: PhD student A: associate fellow E: professor emeritus

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R-A. Field theory

Wigner Research Group

Zoltán Zimborás, Gabriella Böhm, Viktor Czinner^A, László Fehér, Gyula Fodor, Péter Forgács, Gyula Kluge^A, Zoltán Kunszt^A, Árpád Lukács, Balázs Mikóczi, Júlia Nyíri^A, László B. Szabados, Kornél Szlachányi, Kálmán Tóth^A, Gábor Zsolt Tóth, Péter Vecsernyés

Einstein-conformally coupled Standard Model. — We introduced and studied a classical field theoretical model, the so-called Einstein-conformally coupled Standard Model (EccSM), which is general relativistic and in which (according to the key idea above) the matter sector is coupled to gravity in a conformally invariant manner. We showed that, in this theory, in addition to the usual initial Big Bang singularity there might be a so-called Small Bang singularity, too (in which it is only the spacetime geometry is singular but all the matter field variables remain bounded), and that in the generic case Newton's gravitational constant yields an absolute upper bound for the magnitude of the Higgs field. Furthermore, the resulting rest masses of the fields depend on time, and although their time dependence can be neglected soon after their genesis, but about 10 seconds after the initial singularity (which is the characteristic time of the weak interactions) this time dependence could still in principle be shown up in the starting up particle physics processes.

Noether currents for the Teukolsky master equation. — The Teukolsky master equation is an important wave equation that governs the evolution of the extreme spin weight components of the electromagnetic, linearized gravitational, neutrino and spin-3/2 fields in Kerr (i.e., rotating black hole) spacetime. For various purposes, e.g. for testing numerical simulations and for studying the decay properties of the mentioned fields, it is desirable to know conserved currents for this equation. However, the Teukolsky master equation does not follow from a Lagrangian, therefore the usual procedure, which is to apply Noether's theorem, is not suitable for finding conserved currents for it. By applying a less well-known variant of Noether's theorem, we showed that a pair of Teukolsky master equations with opposite spin weights does follow from a Lagrangian, and constructed conserved currents that correspond to the time translation and axial symmetries of the Kerr spacetime and to the scaling symmetry of the Teukolsky master equation. These currents involve two independent solutions of the Teukolsky master equation with opposite spin weights. We also introduced general definitions for the symmetries and conserved currents of boundary conditions of partial differential equations, extended Noether's theorem and its variant to them, and used this extension of the latter variant to construct conserved currents associated with the Sommerfeld boundary condition in the case of the Teukolsky master equation. Such boundary conserved currents are again useful for testing purposes in numerical simulations.

Quantum Correlations in Many-Body Systems. — We studied various types of quantum correlations in many-body systems and field theories. One of these was entanglement negativity, which is a versatile measure of entanglement that has numerous applications in quantum information and in condensed matter theory. It can not only efficiently be computed in the Hilbert space dimension, but for Gaussian bosonic systems, one can compute the negativity efficiently in the number of modes. However, such an efficient computation does

A Associate fellow

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not carry over to the fermionic realm, the ultimate reason for this being that the partial transpose of a fermionic Gaussian state is no longer Gaussian. To provide a remedy for this state of affairs, we introduced efficiently computable and rigorous upper and lower bounds to the negativity, making use of techniques of semi-definite programming, building upon the Lagrangian formulation of fermionic linear optics, and exploiting suitable products of Gaussian operators. We also discussed examples in quantum many-body theory with applications in the study of topological properties at finite temperature.

Another investigated measure was the quantum Fisher information. We calculated the Fisher information quantity for different states of atomic ensembles in a magnetic field, see Fig. 1.

The value of the Fisher information can signal nonclassicality, but it is also important from a metrological point of view. In particular we calculated precision bounds for estimating the gradient of the magnetic field based on the quantum Fisher information. We also considered a single atomic ensemble with an arbitrary density profile, where the atoms cannot be addressed individually, and which is a very relevant case for experiments.

Figure 1. Angular momentum components and their variances for various spin states for few particles are shown: (a) singlet state, (b) z-Dicke state, (c) state totally polarized in the y-direction, (d) x-Dicke state, (e) GHZ state.

Grants

OTKA¹ MAT K 124138 “Crossed modules over Hopf monoids” (G. Böhm, 2017-2021)

OTKA K111697 “Group-theoretic aspects of integrable systems and their dualities” (L. Fehér, 2014-2018)

OTKA PD 116892 "Highly eccentric signals in gravitational wave physics"(B. Mikóczi, 2015- 2018)

International cooperations

Departamento de Álgebra and CITIC, Universidad de Granada, Spain Department of Mathematics, Macquarie University, Sydney, Australia Paris Observatory, Meudon, France

Université de Tours, France

Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, Germany

1 OTKA: National Scientific Research Fund

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Institute of Theoretical Physics and Astrophysics, Faculty of Mathematics, Physics and Informatics, University of Gdansk, Poland

Publications

Articles

1. Böhm G, Gomez-Torrecillas J, Lack S: Weak multiplier bimonoids. APPL CATEGOR STRUCT 26:1 47-111 (2018)

2. Eisert J, Eisler V, Zimborás Z: Entanglement negativity bounds for fermionic Gaussian states. PHYS REV B 97:16 165123/1-12 (2018)

3. Fodor G: Localized objects formed by self-trapped gravitational waves. ASTRON REP+ 62:12 874-881 (2018)

4. Szabados LB, Wolf G: Singularities in Einstein-conformally coupled Higgs cosmological models. GEN RELATIV GRAVIT 50:10 136/1-34 (2018)

5. Szabados LB: On gravity’s role in the genesis of rest masses of classical fields. GEN RELATIV GRAVIT 50:3 Paper: 34 , 21 p. (2018)

6. Apellaniz I, Urizar-Lanz I, Zimborás Z, Hyllus P, Tóth G: Precision bounds for gradient magnetometry with atomic ensembles. PHYS REV A 97:5 053603/1-17 (2018)

Book chapter

7. Böhm G: Hopf algebras and their generalizations from a category theoretical point of view. Lecture Notes in Mathematics, Springer Nature Switzerland AG (2018), pp.

1-165 Other

8. Fehér, L: Poisson-Lie analogues of spin Sutherland models (2018) https://arxiv.org/abs/1809.01529

9. Szabados LB: A gravitációs energia-impulzusról (On gravitational energy- momentum, in Hungarian). FIZIKAI SZEMLE 68:6 183-188 (2018)

See also: R-B.7, R-G.2, S-B.5, S-S.1

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R-B. Heavy-ion physics

Wigner Research Group

Gergely Gábor Barnaföldi, Gergő Almássy, Gábor Balassa, Gyula Bencze^A, Dániel Berényi^#, Gábor Bíró^#, Tamás Sándor Biró, Pál Doleschal^A, Edit Fenyvesi^#, Vahtang Gogohia^A, Miklós Gyulassy^A, Miklós Horváth, Szilvia Karsai^#, Péter Kovács, Róbert Kovács^#, Péter Lévai, Péter Pósfay^#, János Révai^A, K. Shen, Péter Ván, György Wolf, Miklós Zétényi, B. Zhang

High-energy heavy-ion physics is connected to a large variety of physics disciplines. Our researches probe fundamental concepts of classical and modern thermodynamics, hydrodynamics, and quantum theory. Therefore, we have several theoretical and practical topical research directions covering a wide spectrum, such as: thermodynamics, perturbative and non-perturbative Quantum Chromodynamics (QCD), high-energy nuclear effects, hadronization, hadron phenomenology, phenomenology of compact stars, and gravity/cosmology. Our studies are strongly motivated by the needs of several recent and planned largescale facilities, such as collaborations at the LHC (CERN, Switzerland) and RHIC (BNL, USA), and future experiments at FAIR (GSI, Germany) and NICA (Dubna, Russia). We have continued our theoretical investigations in the direction of high-energy physics phenomenology connected to existing and future state-of-the-art detectors. Concerning international theoretical collaborations, we have established joint work with the Goethe Institute (Germany), LBNL (USA), CCNU, MAP (China), UNAM (Mexico), and ERI (Japan). We highlight below some of our major published results in details.

New developments in the effective field theory of the strong interaction. — As a member of the CBM collaboration, we continued the planning of the details of the detector. We participated in the detector simulations concentrated on the phi meson and on the double strange hypernuclei. We studied the physics cases as well.

We proposed a model based on the Statistical Bootstrap approach to estimate the cross sections of different hadronic reactions up to a few GeV in center of mass energy. The method is based on the idea, when two particles collide a so called fireball is formed, which after a short time period decays statistically into a specific final state. We used in a transport model for unknown cross sections.

We studied the masses of the low-lying charmonium states, namely, the J/Ψ, Ψ(3686), and Ψ(3770) in antiproton induced reactions. The masses of these states are shifted downwards due to the second order Stark effect. Using our transport model we showed that the in- medium mass shift can be observed in the di-lepton spectrum. Therefore, by observing the di-leptonic decay channel of these low-lying charmonium states, especially for Ψ(3686), thus one can gain information about the magnitude of the gluon condensate in nuclear matter.

This measurement could be performed at the upcoming PANDA experiment at FAIR as we published.

We analyzed the Xi^- baryon production in subthreshold proton-nucleus (p+A) collisions in the framework of our BUU type transport model. A new mechanism was proposed for Xi production in the collision of a secondary Lambda or Sigma hyperon and a nucleon from the target nucleus. It was found that the Xi^- multiplicity in p+A collisions is sensitive to the

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angular distribution of hyperon production in the primary N+N collision. Using reasonable assumptions on the unknown elementary cross sections we are able to reproduce the Xi^- multiplicity and the Xi^-/(Lambda+Sigma^0) ratio obtained in the HADES experiment.

In connection to cosmology, we studied the time evolution of the Einstein-conformally coupled Higgs cosmological models in the presence of Friedman–Robertson–Walker symmetries. We have found all the analytical singularities. We have shown that beyond the Big Bang singularity (singular curvature and diverging Higgs field there is another new kind of physical spacetime singularity (`Small Bang') where the curvature singular but the Higgs field is finite. Furthermore, we also have shown that there are nonanalytical singularities as well.

Multi-wavelenth astronomy investigations of superdense matter in compact stars.—

Investigation of cold compact stars provides the opportunity to understand cold superdense matter and even, speculate on new states of matter. These theoretical developments are strongly connected to recent measurements of compact stars by multi-wavelength observations and gravitational waves. These projects are supported by theoretical networking EU COST action PHAROS (CA162014).

In collaboration with A. Jakovac (ELTE) we constructed a framework using the Functional Renormalization Group (FRG) technique for a one-fermion and one-boson theory with Yukawa-like coupling, where the equation of state (EoS) was calculated at finite chemical potential and zero temperature exactly – including quantum corrections. We investigated the effect of the quantum fluctuations on the nuclear equation of state and compact star observables. It was demonstrated, that correction to the mean field model can result 30%

difference in the EoS, which modifies the neutron star mass and radius by 5%

(see Fig 1). These interesting results were published in Phys Rev C and an extended study on the compactness in

connection with multiwavelength astronomy measurements of GW170817 were published in PASA.

We started to investigate a realistic Waleckatype mean field model within this new framework. However an alternative gravitational theory, a Kaluza-Klein type compact object were also analyzed in a multifermion framework. This result has been presented on the IAU International Conference. In parallel, the foundations of continuum theories were further researched in non-relativistic, Galilean relativistic and special relativistic spacetimes.

Results from the non-extensive statistical approach. — High-energy heavy-ion collisions are good testbeds for the non-ideal, non-equilibrium, finite systems. The non-extensive statistical Figure 1. Mass-radius diagram of the one- fermion and one-boson theory with Yukawa-like coupling, calculated in the mean field in and FRG framework. Relative difference of the two model is on the side graphs.

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approach, developed by their group, can describe such a matter by enwidening the framework of classical thermodynamics and statistical physics towards non-equilibrium and complex system phenomena. This pioneering, novel approach to Tsallis, Renyi and further non-Boltzmannian entropy formulae have been applied by us in various physical phenomena from heavy-ion collisions, cosmology to networking.

We started a detailed study of the applied Tsallis–Pareto formulae. We found linear relations between the temperature parameter, T and the Tsallis parameter, q−1 , and the logarithmic dependence on the c.m. energy. The quark-hadron channels of the Tsallis–Pareto-like fragmentation functions were also fitted in electron-positron collisions. This result was quite promising, and presented similar values obtained from the fits of the hadron spectra in proton-proton collision. This fragmentation function parametrization was also tested in a direct pQCD calculation. Results were presented at The Hot Quarks Conference.

The entropy production during hadronization of the quark-gluon plasma was also investigated, based on the idea, that at high-energies the pair production and the number of resonances are increasing. We extended the original model with an energy dependent (non- linear) potential (non-constant string force) scenario. This predicts well the beam energy dependence of the total cross section.

The derivation of Cahn-Hilliard equation with Liu procedure clarifies the thermodynamic background of phase field theories and they opened a new approach of deriving them without any variational principles. We analysed the connection between mechanical and thermal continuum phenomena apply the thermodynamic methodology of internal variables and its consequences to develop new numerical methods, to model experimental results and for a comparison with other theories.

Phenomenology, transport, and hydrodynamics for heavy-ion collisions. — We investigated the emergence of the Chiral Magnetic Effect (CME) and the related anomalous current using the real time Dirac-Heisenberg-Wigner formalism. This method is widely used for describing strong field physics and QED vacuum tunneling phenomena as well as pair production in heavy-ion collisions. We investigated the strength of the CME in heavy ion collisions in the energy range of the SPS–RHIC–LHC accelerators, applying the Dirac–Heisenberg–Wigner formalism. The effect is strong and hopefully measurable at the √ =10-60 GeV energy range, starts to become weaker at 130-200 GeV and disappears at LHC energies. Recent experimental data confirms these theoretical results. Final conclusion can be obtained after the analysis of the Beam Energy Scan data at the RHIC accelerator. This result has been published in Phys Lett B.

The dijet acoplanarity was investigated in heavy ion collisions. Nearly back-to-back di-jets with medium or large transverse momenta become acoplanar even in the vacuum due to multi- gluon radiation. This effect could become stronger in hot matter,generated in energetic heavy ion collisions. Thus the acoplanarity could carry information on the opacity of the hot matter.

We described theoretically this dependence and made suggestions for experimental indications of modified acoplanarity. The analysis of recent LHC data may bring new insigth into the understanding of this effect and new data could help to determine the opacity in the real collisions. These result were presented at the Quark Matter 2018.

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A further step was made in the theoretical model of the generalized Fourier-Navier-Stokes system in the framework of non-equilibrium thermodynamics. Solution methods for generalized heat conduction models, and analyzing our related experiments. The detailed analysis of the possible connections with kinetic theory.

In Boltzmann transport model were also investigated together with D. Molnar (Purdue University, USA) and M.F. Nagy-Egri (RMI). We constructed parametrizations of nonlinear 2

→2 transport model results in 0+1D Bjorken geometry, in order to better understand dissipative phase space corrections in kinetic theory and test simplified models/guesses for those commonly used in the literature. It was deemed most immediately suitable for GPGPU calculations because it mainly involves integration in two dimensions only. We studied, how strongly the initial conditions effect the final Tsallis-like distribution and the flow values. These results were presented at the Zimanyi Winter School

An other interesting result of our thermodynamic investigation is related to Schwarzschild black holes. Here we have proved that introducing the volume as a new thermodynamic variable together with a new interpretation of the Bekenstein-Hawking entropy eliminates the negative heat capacity of the original theory. In a countinously accelerating system, similarities with the Unruh temperature were found.

Development for heavy-ion computer simulations. — In collaboration with the University of Berkeley (USA) and IoPP CCNU (Wuhan, China), we finished to develop the HIJING++ heavy- ion Monte Carlo Generator with G. Papp (ELTE), G.Y. Ma (IoPP CCNU), and X.N. Wang (IoPP CCNU, LBNL). The transplantation of the original, 20 years old code from FORTRAN to C++

programming languages was successful. We built a parallel code, providing faster simulations.

The development of the future Monte Carlo generator for the heavy-ion collisions, HIJING++

were reached the stage. The tuning of the nuclear effect for proton-proton (pp) and proton- nucleus (pA) collisions was finished, and we could present first preliminary physics results on pp and pPb collisions in a large and comprehensive study. The predictions were done for the identified hadron production for pPb collisions at 8.16 TeV cm energy in agreement with the experimental data.

Coordination of the ALICE TPC upgrades. — We coordinate the Hungarian contribution to CERN's largest heavy-ion experiment ALICE. This activity is many-folded: In addition to data analysis, our group plays key role in the construction of the world largest, 90 m³-volume, GEM-based TPC for the ALICE and the DAQ O2 upgrade projects.

Operation and Management of the ALICE GRID Tier-2 Center. — We extended our storage capacity: currently 3 storage servers are working. We updated the capacity up to 750TB, all configured and switched online by mid 2018.

Coordination of the MGGL. — Together with the Gravitational Wigner Research Group of the Theory department, we coordinated and organized the establishment of the Matra Gravitational and Geophysical Laboratory of Wigner RCP. This is situated in the Gyöngyösoroszi mine and performs various preparational underground measurements for future, third generation gravitational wave detectors. In 2018, we published the long term data analysis for 2016-2018 in a joint paper, which was submitted to Classical and Quantum Gravity. These data were presented for the LIGO/Virgo collaborations, to the Hungarian

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Academy of Sciences and on various conferences and workshops. In connection to this, we renovated the Janossy pit at the KFKI campus and we started an improved version of the Eötvös experiment.

Education, PR and future. — Connected to our group we had 5 BSc and 7 MSc students. Our young colleagues participated in young researcher's projects and a 4 TDK theses were submitted for the competition: Andras Leitereg (3rd price OTDK, D. Berenyi) and Adam Takacs (G.G. Barnafoldi) awarded the Excellent student Prize of the ELTE TTK 2018), Kovacs Robert got the “Gyorgyi Geza Prize” of the MTA Wigner RCP.

Peter Posfay and Daniel Berenyi passed the Doctoral exams at the Eotvos Univeristy and they preparing their PhD theses for defense. So far we have 6 young PhD fellow in the research group. Senior colleagues are members of the ELTE, BME, PTE doctoral preogrammes. The following group members participated as guest editors: T. S. Biro as editor-in-chief in EPJ A Hadrons and Nuclei, and guest editor of the Wigner Yearbook 2018.

Group members played key role in the following workshop, conference and seminar organizations: “The Future of Many-Core Computing in Science: GPU Day 2018” and “Lectures of Modern Scientific Programming 2018” at the at Wigner RCP of the HAS; “Mechanika a teridőn” space-time summer School;, Zimanyi Winter School 2018 (Budapest, Hungary). T.S.

Biro act as the main organizer of the Wigner Colloquium series for our Institute.

Group members participated in PR activities such as the MAFIHE Schools, the “CERN 25 (HAS), the CREDO tutorial workshop and CERN & Wigner Open Days. We receive regularly invitation by High Schools from Hungary and abroad for PR talks. Besides these activities, we established a good media connection: we participated in several appearances of news, in radio programs, outreach films and on television.

Grants

NKFIH² K-123815: Intelligent particle physics: the birth of hadrons (T.S. Biró, 2017-2020) NKFIH K-124366: Geophysical origin noises in gravitational wave detection (consortium leader: P. Ván, 2017-2020)

NKFIH K-120660: Investigation of the Identified Hadron Production in the Heavy-ion Collisions at the High-luminosity LHC by the ALICE Experiment (G.G. Barnaföldi, 2016-2020)

OTKA K-104260: Particles and intense fields (consortium leader: T.S. Biró, 2012-2017)

OTKA K-116197: Heat transport in extreme media and systems, consortium leader, (P. Ván, 2015-2019)

OTKA K-109462: Theoretical investigations of the strongly interacting matter produced at FAIR (CBM, PANDA) and NICA (Dubna) (Gy. Wolf, 2014-2018)

PANDA and NICA (Dubna) (Gy. Wolf, 2014-2018)

2 NKFIH: National Research, Development and Innovation Office

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International cooperation

HIC for FAIR program participation with Frankfurt University, FIAS and GSI Darmstadt (T.S.

Biro, Gy. Wolf)

UKRAINIAN – HUNGARIAN MTA-UA bilateral mobility program NKM-81/2016 (Hungarian leader: T.S. Biro, Ukrainian leader: L. Jenkovszky).

CERN ALICE experiment, (G.G. Barnafoldi, group leader, and P. Levai)

CERN ALICE TPC and O2 upgrade project, (G.G. Barnafoldi Wigner group leader, 2015-2018) THOR EU COST CA15213 action (Hungarian Representatives: G.G. Barnafoldi – Core member, M. Csanad, 2016-2019)

PHAROS EU COST CA16214 action (Hungarian Representatives: G.G. Barnafoldi – WG Task leader, M. Vasuth, 2017-2021)

Long-term visitors

D. Molnar (G.G. Barnafoldi, 5 months), M. Bejger (G.G. Barnafoldi, M. Vasuth 1 month), Y.

Mao (G.G. Barnafoldi, 1 week), A. Ortiz Velasquez (G.G. Barnafoldi, 1 week), G. Paic (G.G.

Barnafoldi, 1 week), L. Zhu (P. Lévai 1 week), Y. Mao (P. Levai 1 week)

Publications

Articles

1. Albacete JL et al. incl. Barnaföldi GG, Bíró G, Gyulassy M, Harangozó SM, Lévai P [42 authors]: Predictions for cold nuclear matter effects in p+Pb collisions at √ =8.16 TeV. NUCL PHYS A 972: 18-85 (2018)

2. Balassa G, Kovács P, Wolf G: A statistical method to estimate low-energy hadronic cross sections. EUR PHYS J A 54:2 25/1-13 (2018)

3. Berényi D, Leitereg A, Lehel G: Towards scalable pattern-based optimization for dense linear algebra. CONCURR COMP-PRACT E 30:22 e4696/1-14 (2018)

4. Berényi D, Lévai P: Chiral magnetic effect in the Dirac–Heisenberg–Wigner formalism.

PHYS LETT B 782: 162-166 (2018)

5. Biró T, Greiner C, Müller B, Rafelski J, Stöcker H: Topical issue on frontiers in nuclear, heavy ion and strong field physics. EUR PHYS J A 54:2 31/1-3 (2018)

6. Biró TS, Telcs A, Neda Z: Entropic distance for nonlinear master equation. UNIVERSE 4:1 10/1-8 (2018)

7. Biró TS, Czinner VG, Iguchi H, Ván P: Black hole horizons can hide positive heat capacity. PHYS LETT B 782: 228-231 (2018)

8. Biró TS, Schram Z, Jenkovszky L: Entropy production during hadronization of a quark- gluon plasma. EUR PHYS J A 54:2 17/1-10 (2018)

9. Biró TS, Néda Z: Unidirectional random growth with resetting. PHYSICA A 499: 335- 361 (2018)

10. Divotgey F, Kovács P, Giacosa F, Rischke DH: Low-energy limit of the extended Linear Sigma Model. EUR PHYS J A 54:1 5/1-14 (2018)

11. Fülöp T, Kovács R, Lovas Á, Rieth Á, Fodor T, Szücs M, Ván P, Gróf Gy: Emergence of non-Fourier hierarchies. ENTROPY 20:11 832/1-13 (2018)

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12. Gora D et al. incl. Kovács P [21 authors]: Cosmic-ray extremely distributed observatory: status and perspectives. UNIVERSE 4:11 111/1-7 (2018)

13. Kovács R, Ván P: Second sound and ballistic heat conduction: NaF experiments revisited. INT J HEAT MASS TRAN 117: 682-690 (2018)

14. Kovács R: Analytic solution of Guyer-Krumhansl equation for laser flash experiments.

INT J HEAT MASS TRAN 127: 631-636 (2018)

15. Olbrich L, Zétényi M, Giacosa F, Rischke DH: Influence of the axial anomaly on the decay N(1535)  N η. PHYS REV D 97:1 014007/1-18 (2018)

16. Pósfay P, Barnaföldi GG, Jakovác A: Effect of quantum fluctuations in the high-energy cold nuclear equation of state and in compact star observables. PHYS REV C 97:2 025803/1-5 (2018)

17. Pósfay P, Barnaföldi GG, Jakovác A: The effect of quantum fluctuations in compact star observables. PUBL ASTRON SOC AUST 35: e019/1-6 (2018)

18. Révai J: Are the chiral based potentials really energy-dependent? FEW-BODY SYST 59:4 49/1-6 (2018)

19. Rieth Á, Kovács R, Fülöp T: Implicit numerical schemes for generalized heat conduction equations. INT J HEAT MASS TRAN 126: 1177-1182 (2018)

20. Rogolino P, Kovács R, Ván P, Cimmelli VA: Generalized heat-transport equations:

parabolic and hyperbolic models. CONTINUUM MECH THERM 30:6 1245-1258 (2018) 21. Shen K-M, Biró TS, Wang E-K: Different non-extensive models for heavy-ion collisions.

PHYSICA A 492: 2353-2360 (2018)

22. Wolf G, Balassa G, Kovács P, Zétényi M, Lee SH: Mass shift of charmonium states in

̅ collision. PHYS LETT B 780: 25-28 (2018)

23. Zétényi M, Speranza E, Friman B: Polarization and dilepton angular distribution in pion-nucleon collisions. FEW-BODY SYST 59:6 UNSP 138/1-7 (2018)

24. Zétényi M, Wolf G: Influence of anisotropic / creation on the ⁻ multiplicity in subthreshold proton–nucleus collisions. PHYS LETT B 785: 226-231 (2018)

Conference proceedings

25. Bíró G, Barnaföldi GG, Biró TS, Shen K: Mass hierarchy and energy scaling of the Tsallis - Pareto parameters in hadron productions at RHIC and LHC energies. EPJ WEB CONF 171: 14008/1-4 p. (2018) (Proc. 17^th International Conference on Strangeness in Quark Matter (SQM 2017), Utrecht, The Netherlands, July 10-15, 2017.Eds.: Mischke A, Kuijer P)

26. Wolf G, Balassa G, Kovács P, Zétényi M, Lee SH: Charmonium excitation functions in

̅ collisions. ACTA PHYS POL B PROC SUPPL 11:3 531-536 (2018) (Excited QCD 2018, Kopaonik, Serbia, 11-15 March 2018)

27. Zétényi M, Wolf Gy: Subthreshold ⁻ production in proton-nucleus collisions in a BUU model. EPJ WEB CONF 171: 19006/1-4 (2018) (Proc. 17^th International Conference on Strangeness in Quark Matter (SQM 2017), Utrecht, The Netherlands, July 10-15, 2017.Eds.: Mischke A, Kuijer P)

Book chapter

28. Ván P: Weakly nonlocal non-equilibrium thermodynamics: The Cahn-Hilliard equation. In: Generalized Models and Non-classical Approaches in Complex Materials 1, Advanced Structured Materials. Eds.: Altenbach H, Pouget J, Rousseau M, Collet B, Michelitsch T, vol 89, pp 745-760, Springer, Cham

28 Other

29. Biró T, Greiner C, Müller B, Rafelski J, Stöcker H: Topical issue on frontiers in nuclear, heavy ion and strong field physics. EUR PHYS J A 54:2 31/1-3 (2018)

30. Ván P, Fülöp T:The 14^th Joint European Thermodynamics Conference (JETC 2017) J NON-EQUIL THERMODY 43:2 87-87 (2018)

See also: R-A.4, R-L.2

ALICE Collaboration

Due to the vast number of publications of the large collaborations in which the research group participated in 2018, here we list only a short selection of appearences in journals with the highest impact factor.

1. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kiss G, Kőfaragó M, Lévai P, Lowe A, Oláh L, Pochybova S, Varga D, Vértesi R [1040 authors]: D-meson azimuthal anisotropy in midcentral Pb-Pb collisions at √ = 5.02 TeV. PHYS REV LETT 120:10 102301/1-13 (2018)

2. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kőfaragó M, Lévai P, Lowe A, Pochybova S, Varga D, Vértesi R [1016 authors]:

Dielectron production in proton-proton collisions at √ = 7 TeV. J HIGH ENERGY PHYS 2018:9 064/1-47 (2018)

3. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kőfaragó M, Lévai P, Lowe A, Pochybova S, Varga D, Vértesi R [1015 authors]:

Anisotropic flow of identified particles in Pb-Pb collisions at √ = 5.02 TeV. J HIGH ENERGY PHYS 2018:9 006/1-46 (2018)

4 Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kőfaragó M, Lévai P, Lowe A, Pochybova S, Varga D, Vértesi R [1013 authors]:

Inclusive J/ production at forward and backward rapidity in p-Pb collisions at √

= 8.16 TeV. J HIGH ENERGY PHYS 2018:7 160/1-27 (2018)

5. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kőfaragó M, Lévai P, Lowe A, Pochybova S, Varga D, Vértesi R [1003 authors]:

Energy dependence and fluctuations of anisotropic fow in Pb-Pb collisions at √ = 5.02 and 2:76 TeV. J HIGH ENERGY PHYS 2018:7 103/1-39 (2018)

6. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kőfaragó M, Lévai P, Lowe A, Pochybova S, Varga D, Vértesi R [1025 authors]:

Λ production in pp collisions at √s=7 TeV and in p-Pb collisions at √ = 5.02 TeV. J HIGH ENERGY PHYS 2018:4 108/1-48 (2018)

7. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kőfaragó M, Lévai P, Lowe A, Pochybova S, Varga D, Vértesi R [1003 authors]:

Measurement of D⁰, D⁺, D^*+ and D s⁺ production in Pb-Pb collisions at √ = 5.02 TeV.

J HIGH ENERGY PHYS 2018:10 174/1-35 (2018)

8. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kiss G, Varga-Kőfaragó M, Lévai P, Lowe A, Oláh L, Pochybova S, Varga D, Vértesi R [1013 authors]: Transverse momentum spectra and nuclear modification factors of charged particles in pp, p-Pb and Pb-Pb collisions at the LHC. J HIGH ENERGY PHYS 2018:11 13/1-33 (2018)

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9. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kőfaragó M, Lévai P, Lowe A, Pochybova S, Varga D, Vértesi R [1016 authors]:

Measurements of low-p T electrons from semileptonic heavy-flavour hadron decays at mid-rapidity in pp and Pb-Pb collisions at √ = 2.76 TeV. J HIGH ENERGY PHYS 2018:10 61/1-30 (2018)

10. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kőfaragó M, Lévai P, Lowe A, Pochybova S, Varga D, Vértesi R [1017 authors]:

Medium modification of the shape of small-radius jets in central Pb-Pb collisions at

√ = 2.76 TeV. J HIGH ENERGY PHYS 2018:10 139/1-29 (2018)

11. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kiss G, Varga-Kőfaragó M, Lévai P, Lowe A, Oláh L, Pochybova S, Varga D, Vértesi R [1023 authors]: Neutral pion and  meson production in p-Pb collisions at √ = 5.02 TeV. EUR PHYS J C 78:8 624/1-25 (2018)

12. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Varga-Kőfaragó M, Lévai P, Lowe A, Pochybova S, Varga D, Vértesi R [1014 authors]:

Measurement of the inclusive J/ψ polarization at forward rapidity in pp collisions at

√ = 8 TeV. EUR PHYS J C 78:7 562/1-16 (2018)

13. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kiss G, Varga-Kőfaragó M, Lévai P, Lowe A, Oláh L, Pochybova S, Varga D, Vértesi R [1024 authors]: ϕ meson production at forward rapidity in Pb–Pb collisions at √ = 2.76 TeV. EUR PHYS J C 78:7 559/1-18 (2018)

14. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kiss G, Varga-Kőfaragó M, Lévai P, Lowe A, Oláh L, Pochybova S, Varga D, Vértesi R [1010 authors]: Prompt and non-prompt J/ production and nuclear modification at mid-rapidity in p-Pb collisions at √ = 5.02 TeV. EUR PHYS J C 78:6 466/1-17 (2018) 15. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Varga-Kőfaragó M, Lévai P, Lowe A, Pochybova S, Varga D, Vértesi R [1016 authors]:

Inclusive J/ψ production in Xe–Xe collisions at √ = 5.44 TeV. PHYS LETT B 785: 419- 428 (2018)

16. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Varga-Kőfaragó M, Lévai P, Lowe A, Pochybova S, Varga D, Vértesi R [1016 authors]:

Anisotropic flow in Xe–Xe collisions at √ = 5.44 TeV. PHYS LETT B 784: 82-95 (2018) 17. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kiss G, Varga-Kőfaragó M, Lévai P, Lowe A, Oláh L, Pochybova S, Varga D, Vértesi R [1019 authors]: Constraints on jet quenching in p–Pb collisions at √ = 5.02 TeV measured by the event-activity dependence of semi-inclusive hadron-jet distributions. PHYS LETT B 783: 95-113 (2018)

18. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kiss G, Kőfaragó M, Lévai P, Lowe A, Oláh L, Pochybova S, Varga D, Vértesi R [1026 authors]: Longitudinal asymmetry and its effect on pseudorapidity distributions in Pb–

Pb collisions at √ = 2.76 TeV. PHYS LETT B 781: 20-32 (2018)

19. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kiss G, Varga-Kőfaragó M, Lévai P, Lowe A, Oláh L, Pochybova S, Varga D, Vértesi R [1022 authors]: First measurement of Ξ production in pp collisions at √ = 7 TeV.

PHYS LETT B 781: 8-19 (2018)

20. Acharya S et al. incl. Barnaföldi GG, Bencédi G, Berényi D, Bíró G, Boldizsár L, Hamar G, Kiss G, Varga-Kőfaragó M, Lévai P, Lowe A, Oláh L, Pochybova S, Varga D, Vértesi R

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[1019 authors]: Measurement of Z⁰-boson production at large rapidities in Pb–Pb collisions at √ = 5.02TeV. PHYS LETT B 780: 372-383 (2018)

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R-E. Holographic quantum field theory

“Momentum” Research Team

Zoltán Bajnok, Michael Abbott, János Balog, Tamás Gombor^#, Árpád Hegedűs, Zoltán Kökényesi^#, Márton Lájer^#, Haryanto Siahaan, Chao Wu

Subtitle. — Field theoretical derivation of Lüscher's formula and calculation of finite volume form factors

Quantum Field Theories play an important role in many branches of physics. On the one hand, they provide the language in which we formulate the fundamental interactions of Nature including the electro-weak and strong interactions. On the other hand, they are frequently used in effective models appearing in particle, solid state or statistical physics. In most of these applications the physical system has a finite size: scattering experiments are performed in a finite accelerator/detector, solid state systems are analyzed in laboratories, even the lattice simulations of gauge theories are performed on finite lattices etc. The understanding of finite size effects is therefore unavoidable and the ultimate goal is to solve QFTs for any finite volume. Fortunately, finite size corrections can be formulated purely in terms of the infinite volume characteristics of the theory, such as the masses and scattering matrices of the constituent particles and the form factors of local operators.

For a system in a box of finite sizes the leading volume corrections are polynomial in the inverse of these sizes and are related to the quantization of the momenta of the particles. In massive theories the subleading corrections are exponentially suppressed and are due to virtual processes in which virtual particles ``travel around the world'.

The typical observables of an infinite volume QFT (with massive excitations) are the mass spectrum, the scattering matrix, the matrix elements of local operators, i.e. the form factors, and the correlation functions of these operators. The mass spectrum and the scattering matrix is the simplest information, which characterize the QFT on the mass-shell. The form factors are half on-shell half off-shell data, while the correlation functions are completely off- shell information. These can be seen from the Lehmann-Symanzik-Zimmermann (LSZ) reduction formula, which connects the scattering matrix and form factors to correlation functions: The scattering matrix is the amputated momentum space correlation function on the mass-shell, while for form factors only the momenta, which correspond to the asymptotic states are put on shell. Clearly, correlation functions are the most general objects as form factors and scattering matrices can be obtained from them by restriction. Alternatively, however, the knowledge of the spectrum and form factors provides a systematic expansion of the correlation functions as well.

The field of two dimensional integrable models is an adequate testing ground for finite size effects. These theories are not only relevant as toy models, but, in many cases, describe highly anisotropic solid state systems and via the AdS/CFT correspondence, solve four dimensional gauge theories. Additionally, they can be solved exactly and the structure of the solution provides valuable insight for higher dimensional theories.